Use Cramerʹs Rule to Solve the System of Equations $$\begin{array} { r } x + y + z = - 1 \\x - y + 3 z = 7 \\3 x + y + z = - 3\end{array}$$

Multiple Choice

Use Cramerʹs rule to solve the system of equations. If D = 0, use another method to determine the solution set.
- $$\begin{array} { r } x + y + z = - 1 \\x - y + 3 z = 7 \\3 x + y + z = - 3\end{array}$$

A) $\{ ( 2 , - 2 , - 1 ) \}$
B) Cramer's rule does not apply since $\mathrm { D } = 0$ ; $\varnothing$
C) $\{ ( - 1 , - 2,2 ) \}$
D) $\{ ( 2 , - 1 , - 2 ) \}$